Drill bit



M y 1950 c. c. GOOLSBEE 2,507,439

DRILL BIT Filed Sept. 28, 1946 6 FIGS 16 CHARLES C. G OOLSBEE INVENTOR.

4 ATTORNEYS Patented May 9, 1950 UNITED STATES PATENT OFFICE DRILL BIT Charles C. Goolsbee, Houston, Tex., assignor to Reed Roller Bit Company, Houston, Tex., a corporation of Texas Application September 28, 1946, Serial No. 699,980

1 Claim.

This invention relates to rotary drilling bits and will be found particularly useful in deep well drilling.

A conventional type of drill bit includes a bit head on the lower end of which are mounted a plurality of cutting blades, the bottom edges of which extend across the bottom of the bit and beyond opposite sides of the head at substantially right angles to the axis of the head. Since the inner area of the bottom of the hole upon which the blades operate is smaller than the outer area of the bottom of the hole, the outer portions of the blades have more work to do and consequently wear more quickly than do the inner portions. A bit thus worn does not operate efiiciently.

Conventional drill bits heretofore provided have included two oppositely disposed blades known as the two-way bit, and four oppositely disposed blades known as a four-way bit. It is desirable to use a two-way bit in certain formations and a four-way bit in others.

This invention has for one of its general objects the provision of a new and improved drill bit in which two blades or four blades may be used as desired.

Another object of the invention is to provide a four-way bit in which all Of the four blades operate upon the outer area of the bottom of the hole and only two of the blades operate upon the inner area of the bottom of the hole, to thereby prevent wearing of the outer portions of the blades before the inner portions are worn.

The blades of bits of this type are usually welded on the bit head, and this invention has for another of its objects the provision of a new and improved construction whereby the blades will be held in alignment while being welded to the head, to the end that when the welding operation is completed the blades will be in precisely the desired positions on the head.

Other objects will hereinafter appear.

The preferred embodiment of the invention is illustrated in the accompanying drawings in which Fig. l is a partly sectional elevation of the bit taken on the line l-l of Fig. 2; Fig. 2, a bottom plan view; Fig. 3, a fragmentary elevation of the bit taken on the line 33 of Fig. 2; Fig, 4, an elevation of the outer area cutting blade; and Fig. 5, an elevation of the outer and inner area cutting blade.

In th drawings, the numeral l indicates the bit head which may be provided as indicated at 2 in Fig. 1 with internal threads whereby it may be attached to the lower end of a conventional drill stem (not shown) The cutting blade to cut substantially the entire area of the bottom of the hole is indicated at 3 in Fig. 5. It has oppositely disposed upper projections or parts 4 to be welded as indicated at 1 to oppositely disposed peripheral shoulders 5 of the bit head (Figs. 1 and 3). It has a cutting edge 6 extending across the bottom of the head and beyond opposite sides of the head. And this cutting edge 6 is substantially at a right angle to the longitudinal axis of the head. This blade 3 also has a central downwardly opening slot 8 for the reception of the blade 9 shown in Fig. 4.

The blade 9 also has oppositely disposed upper projections H] which are welded to oppositely disposed peripheral shoulders ll of the head as indicated at l2 in Fig. 3. This blade 9 has a central web portion l3 shaped in the nature of a reverse curve to enter the slot 8 and it has cutting edges l4 to out only the outer area of the bottom of the hole.

The bit head I may be provided with slush passageways I5 to direct slush upon the blades 3 and 9 when it is pumped through the drill stem (not shown) in the usual manner.

In those formations in which the driller wishes to use the so-called two-way bit, that is a bit having only two blades one on each side of the head, the blade 3 alone may be used and the cutting edges 6 will perform the desired function.

When the driller wishes to use a so-called fourway bit, that is, a bit having four cutting blades, the cutting blade 9 may be placed in the slot 8 of the blade 3 and welded to the head to provide the additional cutting edges I 4 to perform the desired function. And since the cutting edges I4 do not extend substantially to the longitudinal axis of the head as do the cutting edges 6 of blade 3 the bit provides four cutting edges to cut the outer area of the bottom of the hole and only two cutting edges to cut the inner area of the bottom of the hole. Since the outer area is much larger than the inner area and more work is required of the blades in the cutting of the outer area than is required in the cutting of the inner area, this arrangement will result in a substantially even wearing of the blades so that the cutting edges will remain at substantially a right angle of the axis of the head, and the outer portions of the blades will not be rounded off as heretofore.

Referring now to the new and improved construction whereby the blades are held in alignment while being welded to the head, it will be noted that the blade 3 shown by Fig. 5 has a central projection extending slightly upwardly and indicated at It. This projection It has a flat upper surface. When the blade 3 is placed on the head the projection it enters the recess I1 (Fig. 1). It will be understood that the head I may be placed upside down on the floor and the blade 3 is then placed on top of the bottom of the head so that the projection 15 will enter the recess 11 and the fiat surface of the projection IE will rest upon the flat surface of the recess 11. If desired, the head 1 may be provided with a bore 18 and the blades 3 and 9 with bores l9 and I9a respectively and a pin may be inserted in these bores to provide a further support for the blades while they are being welded on the head, but the projection Hi fitting in the recess I! will support the blade 3 when that blade alone is used. When the blade 9 is used with the blade 3 a pin will be found useful in more securely holding the blades together in position on the head.

The invention is not limited to the preferred embodiment herein disclosed. Various changes may be made within the scope of the following claim.

I claim:

A rotary drill bit for drilling a well bore comprising, a bit head having four substantially equally spaced peripheral shoulders at its lower end with said shoulders being arranged in opposed pairs on opposite sides of the head, a blade adapted to be secured to the lower end of the head and having upwardly extending projections abutting and welded to two of the peripheral shoulders, said blade having a substantially continuous cutting edge interrupted only by a downwardly opening central slot and extending at substantially a right angle to the longitudinal axis of the head with the ends of said blade projecting in planes beyond the side of the head, and a second blade having upwardly extending projections abutting and welded to the other two of the peripheral shoulders, said second blade having a pair of cutting edges on opposite ends of its lower portion, and a central web portion connecting the cutting edges and engageable within the downwardly opening slot in the first blade when said second blade is secured in position on the head, the two cutting edges of the second blade terminating in a plane spaced from the axis of the bit head.

CHARLES C. GOOLSBEE.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,400,132 Agassiz Dec. 13, 1921 1,746,423 Hartman Feb. 11, 1930 1,889,216 Reed Nov. 29, 1932 2,040,263 Layne et a1 May 12, 1936 2,055,145 Christian Sept. 22, 1936 2,056,319 Harrington Oct. 6, 1936 2,090,058 Mangels Aug. 17, 1937 2,132,493 Phipps Oct. 11, 1938 2,329,461 Flynn Sept. 14, 1943 

